Current view: Data table and detailed info
Taxonomic source(s)
Christidis, L. and Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. CSIRO Publishing, Collingwood, Australia.
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
IUCN Red List criteria met and history
Red List criteria met
Red List history
| Migratory status |
not a migrant |
Forest dependency |
medium |
| Land-mass type |
|
Average mass |
841 g |
Population justification: The global population size has not previously been accurately estimated but it remains regularly observed through its range (eBird 2022). In Australia, the endemic taxon macgillivrayi is reliably estimated to number 1,800-2,600 mature individuals, with a best estimate of c.2,200 (Heinsohn et al. 2021). Robust population data on the other three recognised subspecies are lacking, although nest densities of 0.8/km2 were recorded in Papua New Guinea (Igag et al. 2019), equivalent to c.1.6 mature individuals/km2. Across the range (excluding Cape York, Australia, for which other data are available), there is a large area of ostensibly suitable habitat, amounting to c.400,000–500,000 km2 of forest depending on the tree cover percentage used (per Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein). Assuming the densities collated at a single site in Papua New Guinea are representative for elsewhere in New Guinea (including satellites), and that only a percentage (arbitrarily set here to 40–80%) of the range is occupied, the population is estimated to number c.260,000–640,000 mature individuals.
Trend justification: This species is inferred to be in decline due to a plethora of threats across its range.
Although it represents only a small portion of the global population, the most robust data are available from Australia, where data are consistent in demonstrating the species is likely to be in severe decline (Heinsohn et al. 2009, 2021; Keighley et al. 2021). Over a slightly longer three-generation timeframe than that used here (49 vs 47 years), Keighley et al. (2021) used population viability analysis to predict a 46.7-94.5% future decline in the meta-population, and a 74.2–93.8% decline in the Iron/McIllwraith population; the authors favoured models that ultimately predicted more precise declines of 55.1–55.6% and 80.3–82.9% respectively. The principal cause of these declines is habitat loss (caused by clearing for bauxite mining), a changing fire regime, competition with Cacatua galerita and increasing storm severity/frequency (Heinsohn et al. 2021); however, none of these threats are thought to be impacting populations in New Guinea, where >95% of the population resides.
In New Guinea, the chief threats are habitat loss and trapping for the pet trade. Between 2000 and 2021, habitat loss in the non-Australian part of the species' range amounted to c.5%, equivalent to c.10-11% over three generations. However, this accelerated from 2014 to a rate equivalent to 14% over three generations and there is concern this could accelerate further if patterns observed in Indonesian Borneo over the last three decades are mirrored (Gaveau et al. 2021). Moreover, this species has bespoke nesting requirements, apparently favouring deep hollows with an open-skyward facing entrance (Igag et al. 2019), that may be heavily impacted by selective logging, a key threat in New Guinea's lowlands (Testolin et al. 2016) that is not accurately detectable using remote sensing data. The impact of trapping for the pet trade remains similarly unquantified, but both local (Pangau-Adam and Noske 2010) and international (Sy 2010) trade of this species has been documented. Although large areas of habitat remain impenetrable to local trappers, ongoing fragmentation and increasing accessibility via road infrastructure (Gaveau et al. 2021) are likely to make this an accelerating threat. This species breeds extremely slowly, producing only a single egg in any clutch and, at one site in Papua New Guinea, was estimated to nest only once every six years (Igag et al. 2019). Consequently, even low rates of trapping are likely to have a substantial impact on the population, especially if mature breeding adults are targeted. Evaluating the available data, the species is suspected to decline by 20–29% in the next three generations (47 years; Bird et al. 2020).
Country/territory distribution
Important Bird and Biodiversity Areas (IBA)
Recommended citation
BirdLife International (2024) Species factsheet: Palm Cockatoo Probosciger aterrimus. Downloaded from
https://datazone.birdlife.org/species/factsheet/palm-cockatoo-probosciger-aterrimus on 22/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 22/12/2024.
